No matter how accurate the spray fluxer is there will at least be some flux that is not deposited on the board that needs to be removed from the system. I mentioned in my previous post that all spray fluxer setups need to have their own venting system, separate from the soldering station vent system.
The diagram that I created here shows a simple schematic of what the venting system might look like. The horizontal plates, the first filters in the vent, are removable and can be cleaned of the flux residue. Some of the more sophisticated systems may have three or more plates. Some flux may be able to bypass the plates and get into the duct work. That is why it is important to have a system that can be easily disassembled and thoroughly cleaned. If the flux is not removed it can pose a fire and safety hazard. In the event of a fire, the duct work should have a fusible link that would shut off the vent fans. Also, since the flux can be very corrosive, the material you use for the vent and duct-work should be considered appropriately.
Next week I will be talking about brush fluxers.